Wildlife photography is mostly a problem of time and light, and both are decided before you ever pick up a camera. They are decided by where you sleep.

The first hour
The best light in the Mara lasts about ninety minutes after sunrise. A camp inside the reserve puts you among animals within minutes of leaving. A camp beyond the gates spends forty to ninety minutes driving in, and arrives as the light goes flat.
That is the whole argument, and everything else follows from it. Ilora sits in the central Olkiombo, ten minutes from the main river crossing. You are on subject at first light, and back for a slow breakfast rather than three hours into a transfer.
Time on subject
The shot that works is almost never the first one. It is the ninetieth, after an hour with the engine off, when the leopard finally stands up.
Being close to camp is what makes that hour affordable. You can wait, because you have not spent your morning getting there and you are not calculating the drive back. You can go out all day with food in the vehicle. You can come back at three for the second light.

The guide is half the photograph
A guide who understands photography does something a spotter does not: positions the vehicle for the light rather than the view, anticipates which way an animal will move and gets there first, and knows when to stop the engine so the vibration is out of your long lens.
Ask before you book whether the camp’s guides work with photographers regularly. The answers vary enormously, and it matters more than the vehicle.
What the Mara gives you that other reserves do not
Open country and clean sightlines. In forested reserves you photograph through vegetation; here you photograph across it, with a horizon and a sky doing real work in the frame. Acacia for framing, escarpment for depth, and dust and backlight in the evening that you cannot manufacture.
Around 95 species of mammal and more than 450 of bird, including lilac-breasted roller, secretarybird, Kori bustard and 57 raptors. Between July and October, roughly 1.5 million wildebeest arrive from the Serengeti, followed by everything that eats them.

When to come, depending on what you want
July to October. Short grass, clear sightlines, the herds, and the river crossings. Also the busiest and most expensive months, and at popular sightings you will share the frame’s foreground with other vehicles.
November to March. Green background, dramatic skies, migratory birds, cats with cubs, and far fewer people. For portraits rather than action, this is the better season and most photographers who return come now.
April and May. The long rains. The greenest and emptiest the Mara gets, with the lowest rates. Heavy rain will cost you drives, and some roads become impassable.
Time of day, in every season: the ninety minutes after sunrise and the hour before dusk. Between ten and four the cats sleep and the light is unusable for anything except the sky.

Inside the reserve or in a conservancy
This is asked constantly and usually answered dishonestly by whoever is selling you the room. Both have real advantages.
Inside the reserve you are with the game from the moment you leave camp, you pay no additional entry fee to reach the main river circuits, and you have access to the Mara Triangle, the Talek and the crossing points without transferring. During the migration this is decisive, because the crossings happen on reserve ground. The reserve also holds the highest game density in the ecosystem.
In a conservancy you get fewer vehicles per acre, and two things the reserve prohibits outright: night drives and walking safaris. Off-road driving is permitted in most conservancies and banned in the reserve, which for a photographer is a genuine advantage on a low-light sighting. Conservancies are not fenced — they are open to the same wildlife — but you will pay a separate reserve entry fee on the days you want to reach the river.
Neither is simply better. If you are here for the crossings, stay in the reserve. If you are here for a leopard at night or a morning on foot, stay in a conservancy. Many photographers split the trip, which is what we usually suggest.

Outside the drives
The camera does not need to go away when the vehicle stops. Elephant move past below the sky deck, the riverine forest around the tents holds more birds than most people photograph all week, and hippo are audible all night from the river.

If photography is the reason you are coming rather than a souvenir of the trip, where you sleep is not indulgence. It is arithmetic: minutes of good light, divided by minutes spent driving to reach it.